1. Field of the Application
The present application relates to the field of turbomachine de-icing. More precisely, the present application deals with a splitter lip for an axial turbomachine. The present application also considers an axial turbomachine fitted with a de-icing splitter lip.
2. Description of Related Art
Turbofan engines have been developed to care for the environment. Care for the environment is in this case intended to mean limiting noise and reducing consumption. With a view to optimizing their thrust and performance while reducing noise, jet engines use multiple annular air flows. Generally, a turbomachine splits an incoming air flow into a primary flow and a secondary flow in the form of annular sleeves. The primary flow passes through the compressors, a combustion chamber and is then expanded in turbines. The secondary flow passes around the outside of the compressor, the combustion chamber and the turbine, and then joins the primary flow at the exit from the jet engine. The flows are split by a circular splitter lip placed upstream of the compressor; the shape of this lip limits the amount of air entering the compressor.
The air entering the turbomachine is still at ambient temperature at the splitter lip. Since these temperatures can drop to −50° C. at altitude, humidity can cause ice to form on the lip. In flight, this ice can grow and accumulate until it forms blocks on the upstream side of stator vanes of the compressor. These blocks can also alter the shape of the lip and influence the air flow entering the compressor, which can impair the performance of the latter.
As they develop, the blocks can become particularly large and then detach due to the vibrations of the turbomachine. The incoming flow can cause these blocks to be ingested by the compressor, with the concomitant risk of damage to the rotor blades. This ingestion is particularly harmful as it does not pass through the fan beforehand. In order to limit this ice formation, splitter lips are provided with a de-icing device.
EP 1942249 A2 discloses a splitter lip for an axial turbomachine provided with a fan. The splitter lip comprises a de-icing system with a network of pipes coupled to a hot source. The pipes are in contact with the splitter lip and are held there with the aid of supports. Silicone material is placed between the support and the pipes in order to obtain a shock-absorbing effect so as to isolate the pipes from vibrations. This means that thermal conduction between the lip and the pipes is not optimal, resulting in impaired de-icing.
Although great strides have been made in the area of turbomachine de-icing, many shortcomings remain.